Due to energy conservation awareness of the public and the building industry, new standards for energy efficient buildings include more stringent requirements on air tightness, insulation, mechanical ventilation, air quality, and space heating-cooling loads.
As the loads for heating-cooling of the more energy efficient housing has been reduced, their air tightness brought up a need for a continuous mechanical exchange of indoor air with outdoor air to avoid potential health hazards and or house damage problems. Consequently, ventilation of new houses has become one of the required standard air conditioning services.
At present the space heating services in houses and large buildings are provided by various makes of appliances or systems including conventional warm air central heating, hydronic or water circulating central heating systems or an electric or fossil fuel fired unitary systems. For the central systems energy sources may be any fossil fuel or electric power, and the central furnaces and boilers may be conventional, high efficiency or ultra high efficiency condensing types.
The cooling systems may include indirect, direct or a combination of indirect-direct evaporative cooling systems, absorption chillers and mechanical compression systems with the absorption and mechanical compression systems providing simultaneously the required dehumidification and with the evaporative cooling systems providing the required humidification.
The required ventilation is provided by various heat recovery ventilation systems build around various types of air to air heat exchangers equipped with defrost controls and with various effectiveness ratings. At below freezing temperatures the majority of these systems suffer build up of ice causing significant reduction in the heat recovery effectiveness and air delivery capacities.
The space heating, cooling and ventilation services provided by various individual appliances or by integrated systems are capital expensive and are increasing the buildings' capital and operating costs.
Considerable technical literature is available on the heat and mass transfer theory and design and operation of the various heating systems and the indirect-direct evaporative cooling systems. The packed bed regenerative heat exchangers and dryers are described in detail in W. M. Kays, A. L. London, "Compact heat exchangers", McGraw Hill Co., sec. ed., 1964; W. H. McAddams, "Heat Transmission" 3rd ed., McGraw Hill Book Co., 1954; P. C. Wancat, "Large-scale Adsorption and Chromatography", CRC Press Inc., 1986.
Examples of packed bed collecting and releasing of heat in a continuous cyclic operation are the check-work regenerators used with the steel and glass melt furnaces and for transferring of moisture the various desiccant based air dryers and sorption separation systems used by process industries.
Systems involving heat transfer use a matrix which may be a fixed bed, a moving bed, or a rotating bed which may be a disc, drum or wheel and containing a suitable heat and moisture absorbing material.
The fixed bed systems may use a single, two, or more fixed packed beds of solid materials, and are provided with a quick closing valve arrangement and ducting permitting the cycling of the two air streams between the individual beds.
The fixed bed systems due to the inherent simplicity of the fixed bed are widely used in industrial process applications, however, the required quick closing valving and the required ducting is expensive, subject to wear and considerable maintenance, and a source of significant loss of energy.
The present invention which is utilizing the fixed bed heat transfer theory in achieving the ultra high energy efficient heating and cooling of air, therefore has as one of its objects the provision of an improved apparatus for high energy efficient heating and indirect-direct evaporative cooling of air at reduced capital and operating costs.
Another object is the provision of a compact apparatus for ultra high energy efficient heating of air that would eliminate the possibility of leakage and contamination of the heated air by combustion products.
Another object is the provision of an apparatus for high energy efficient heating of air that would achieve the ultra-high energy efficiency with avoiding the condensation of the moisture present in combustion products to eliminate the condensate corrosion problems.
Another object is the provision of a simple, inexpensive and high energy efficient apparatus for indirect-direct evaporative cooling of air.
Another object is the provision of an apparatus for cooling of air under conditions of high temperature-high humidity, when the indirect-direct evaporative cooling is ineffective.
Another object is the provision of an apparatus capable of providing the indirect-direct evaporative cooling of air during the periods When the humidity of the ambient air is low, and provide the enhanced evaporative cooling only during the periods when the humidity of the air is high.
Another object is the provision of a compact high energy efficient apparatus for the alternate heating of the air for heating and ventilation of a building during the winter heating season, and cooling of the air for cooling and ventilation of the building during the summer cooling season.
Another object is the provision of a packed bed system that does not require the quick closing valves and the associated ducting.
Still another object is the provision of a compact apparatus for heating, cooling and ventilation of a building suitable for use in small scale installations such as expected in private dwellings or homes, apartment houses, office buildings or the like, as well as in large scale commercial, industrial, residential and institutional buildings and or industrial plants that would operate quietly.
Another object is to provide an apparatus for heating, cooling and ventilation of buildings which requires the simplest ducting and instrumentation.
Another object is the provision of the apparatus that would save fuel and power in heating, cooling and ventilation of buildings.
In the heating, cooling and ventilation field, there have been numerous proposals for improvements in heating, cooling and ventilating systems, and the following U.S. patents were considered in preparation of this application:
U.S. Pat. No. 1,658,198 (J. C. Hosch, Feb. 7, 1928) PA1 U.S. Pat. No. 2,121,733 (Cottrell, F. G., June 21, 1938) PA1 U.S. Pat. No. 2,242,802 (Stramaglia, N., May 20, 1941) PA1 U.S. Pat. No. 3,452,810 (Schmidt, J. H. et al, July 1, 1969) PA1 U.S. Pat. No. 3,870,474 (Houston, R. Mar. 11, 1975) PA1 U.S. Pat. No. 4,398,590 (Leroy, M., Aug. 16, 1983) PA1 U.S. Pat. No. 4,227,375 (Tompkins, L., et al. Oct. 14, 1980) PA1 U.S. Pat. No. 4,299,561 (Stokes, K. J., Nov. 10, 1981) PA1 U.S. Pat. No. 4,596,284 (Honmann, W., June 24, 1986) PA1 U.S. Pat. No. 4,708,000 (Besik, F., Nov. 24, 1987) PA1 U.S. Pat. No. 4,711,097 (Besik, F., Dec. 8, 1987)